Our simulation topology is pictured in Figure 6. A cluster of sending agents is labeled through , with its local aggregation point labeled . A remote cluster of ACK (acknowledgement) agents is labeled through , with its aggregation point labeled . and are intermediary nodes used to create a congested link, and and are used for traffic generation.
Propagation delay on links -, -, and - is configured to be 4 msec, while it is only 1 msec on links - and -. The link capacity for all links is 10 Mb/s, except for links - and - where link capacity is 100 Mb/s. This allows traffic generators to increase traffic over link - to any desired level.
Trace data is collected as it is transmitted from to since this allows us to observe sending rates before additional traffic on the link - causes queuing delays, drops, or jitter not reflective of cluster endpoint sending rates.
TCP and C-TCP flows in this section use an infinitely large data source and send at the maximum rate allowed by their respective algorithms. Congestion periods are created by configuring and to generate constant bitrate traffic across the link -. In particular, a CBR agent sending at a constant 7.5-9.0 Mb/s from to competes with data traffic from - over link -.